Answer:
One of the most widespread beliefs about fossil fuels — oil, natural gas and coal — is that these substances started out as dinosaurs. There’s even an oil company, Sinclair, that uses an Apatosaurus as its icon. That dino-source story is, however, a myth. What is true: These fuels got their start long, long ago — at a time when those “terrible lizards” still walked the Earth.
Fossil fuels store energy in the bonds between the atoms that make up their molecules. Burning the fuels breaks apart those bonds. This releases the energy that originally came from the sun. Green plants had locked up that solar energy within their leaves using photosynthesis, millions of years ago. Animals ate some of those plants, moving that energy up the food web. Others plants just died and decayed.
Any of these organisms, when they die, can be turned into fossil fuels, notes Azra Tutuncu. She’s a geoscientist and petroleum engineer at the Colorado School of Mines in Golden. But it takes the right conditions, including an oxygen-free (anoxic) environment. And time. A whole lot of time.
The coal we burn today got its start some 300 million years ago. Back then, dinosaurs roamed the Earth. But they didn’t get incorporated into coal. Instead, plants in bogs and swamps died. As this greenery sunk to the bottom of those wet areas, it partially decayed and turned into peat. Those wetlands dried out. Other materials then settled down and covered the peat. With heat, pressure and time, that peat transformed into coal. To extract coal, people now have to dig deeply into the earth.
Ancient living organisms are buried quickly and altered by intense heat and pressure to form fossil fuels. Fossil fuels include solid coal, liquid petroleum, and liquid natural gas.
Source; Goo_gle
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Evaluate tan(249).
O A. 1.36
B. 0.45
C. 0.41
D. 0.91
Answer:
tan 249 = 2.61
tan 249 = tan (249 - 180) = tan 69 = 2.61
() The two forces F_{1} and F_{2} shown in Fig. 4- 39a and b (looking down) act on a 27.0-kg object on a frictionless tabletop . If F_{1} = 10.2N and F_{2} = 16.0N find the net force on the object and its acceleration for each situation , (a) and (b) .
In a game of tug of war, team one pulls to the right with a force of 500 newtons and team two pulls to the left with a force of 600 newtons. What is the net force?
Answer:
Explanation:
There is no set way to do this. All you have to do is define left and right. Left will be minus and right will be the opposite --- plus.
That is completely arbitrary. It could be the other way around. It does not matter.
Left is minus so: - 600 N is the force going left.
Right plus so: + 500 N
Now just add.
Net Force = +500 - 600
Net Force = - 100 N
So the Net Force is - 100 N going to the left.
The image shows mountains in Alaska.
Which describes the main feature of the circled area of these mountains?
A syncline is visible.
An anticline is visible.
These mountains show no evidence of folding.
These mountains likely formed from normal faults
Answer:
A syncline is visible.
Explanation:
A syncline is visible.
Answer:
These mountains show no evidence of folding.
Explain what is meant by the elastic limit of a spring.
Answer:
The elastic limit of a material is the furthest
point it can be stretched or deformed while
being able to return to its previous shape.
Explanation:
Once a material has gone past its elastic
limit, its deformation is said to be inelastic.
The higher the spring constant, the stiffer
the spring.
What is the kinetic energy of a 36N toy car which is moving at 5 m/s?
Bob is riding in a roller coaster, and is at the top of a vertical loop (shown below). The radius of the loop is 18 meters. If his apparent weight is just 28% of his actual weight, what is the speed of the roller coaster? Show all your steps.
What is the most likely reason for some antelope to employ selective brain cooling
Answer:
The brain is a part of the body that is particularly sensitive to high temperature. Hence some ungulates, like the Thomson's gazelle, use a counter-current heat exchanging structure known as the carotid rete to keep the brain cooler than the body.The cooled arterial blood then continues toward the brain.
3)
Car A, moving in a straight line at a constant speed of 20. meters per second, is initially 200
meters behind car B, moving in the same straight line at a constant speed of 15 meters per
second. How far must car A travel from this initial position before it catches up with car B?
A)
200 m
B)
1000 m
C)
800 m
D)
400 m
Answer:
C) 800
Explanation:
What happened to an enzyme’s structure as it exceeds the typical human body temperature
Enzymes. ... This is because heat energy causes more collisions, with more energy, between the enzyme molecules and other molecules. However, if the temperature gets too high, the enzyme is denatured and stops working. A common error in exams is to write that enzymes are killed at high temperatures.
A rock falls to the ground with a force of 300N and air resistance pushes back up on the rock with a
force of 45N. Which is true of the rock?
A There are balanced forces acting on the rock and the net force is 255N down
B. There are unbalanced forces acting on the rock and the net force is 255N down
C. There are balanced forces acting on the rock and the net force is 345N down
. There are unbalanced forces acting on the rock and the net force is 345N down
Answer:
c
Explanation:
Which of the following is the current best hypothesis for the formation of the solar system?
A. Formed by an exploding super nova star which then collapsed and coalesced into a spinning
disk forming Sun and planets
B. Our solar system has always been here and has never changed
C. Formed from the Sun’s explosion releasing particles into space forming planets and other
objects
D. Our solar system was formed by a great collision of other stars with one another
Answer:
A
Explanation:
all galaxies exploded in order to create the sun/stars
chứng minh mặt trời là nguồn gốc của tất cả nguồn năng lượng
An Excerpt from “Optimism”
by Helen Keller
1 Could we choose our environment, and were desire in human undertakings synonymous with
endowment, all men would, I suppose, be optimists. Certainly most of us regard happiness as
the proper end of all earthly enterprise. The will to be happy animates alike the philosopher, the
prince and the chimney-sweep. No matter how dull, or how mean, or how wise a man is, he feels
that happiness is his indisputable right.
2 It is curious to observe what different ideals of happiness people cherish, and in what singular
places they look for this well-spring of their life. Many look for it in the hoarding of riches, some
in the pride of power, and others in the achievements of art and literature; a few seek it in the
exploration of their own minds, or in the search for knowledge.
3 Most people measure their happiness in terms of physical pleasure and material possession.
Could they win some visible goal which they have set on the horizon, how happy they would be!
Lacking this gift or that circumstance, they would be miserable. If happiness is to be so
measured, I who cannot hear or see have every reason to sit in a corner with folded hands and
weep. If I am happy in spite of my deprivations, if my happiness is so deep that it is a faith, so
thoughtful that it becomes a philosophy of life,—if, in short, I am an optimist, my testimony to
the creed of optimism is worth hearing....
4 Once I knew the depth where no hope was, and darkness lay on the face of all things. Then
love came and set my soul free. Once I knew only darkness and stillness. Now I know hope and
joy. Once I fretted and beat myself against the wall that shut me in. Now I rejoice in the
consciousness that I can think, act and attain heaven. My life was without past or future; death,
the pessimist would say, “a consummation devoutly to be wished.” But a little word from the
fingers of another fell into my hand that clutched at emptiness, and my heart leaped to the
rapture of living. Night fled before the day of thought, and love and joy and hope came up in a
passion of obedience to knowledge. Can anyone who has escaped such captivity, who has felt
the thrill and glory of freedom, be a pessimist?
5 My early experience was thus a leap from bad to good. If I tried, I could not check the
momentum of my first leap out of the dark; to move breast forward is a habit learned suddenly
at that first moment of release and rush into the light. With the first word I used intelligently, I
learned to live, to think, to hope. Darkness cannot shut me in again. I have had a glimpse of the
shore, and can now live by the hope of reaching it.
6 So my optimism is no mild and unreasoning satisfaction. A poet once said I must be happy
because I did not see the bare, cold present, but lived in a beautiful dream. I do live in a
beautiful dream; but that dream is the actual, the present,—not cold, but warm; not bare, but
furnished with a thousand blessings. The very evil which the poet supposed would be a cruel
6) Read the last sentence from the text.
Only by contact with evil could I have learned to feel by contrast the beauty of truth and love and goodness.
Explain how Helen Keller develops this idea in the text. Use specific details to
support your answer.
I NEED A 100% ACCURATE ANSWER FOR THIS QUESTION ASAP NO LINKS !!!
What is defined by force per unit area?
1: gravity
2: force
3: temperature
4: pressure
Answer:
4. pressure is defined as force per unit area
Pressure is defined by force per unit area.
WHAT IS PRESSURE:Pressure refers to the force applied to a substance per unit area. Force is measured in Newtons (N) while area is measured in m², hence, the unit of pressure is N/m² also called pascal.Therefore, according to this question, it can be said that pressure is defined by force per unit area
Learn more about pressure at: https://brainly.com/question/356585
A baseball is traveling with a velocity of 12 m/s at an angle of 45 above
horizontal. What is the velocity of the ball after two seconds?
Focus on the ball. Do you see you? Keep following it. Put all your energy into watching it and then unlock your third eye. With that you'll be able to determine your question.
Show your workikkkkkkkk
Answer:
Explanation:
F = ma
Assuming the 20° is angle θ measured to the horizontal
mgsinθ - μmgcosθ = ma
g(sinθ - μcosθ) = a
at constant velocity, a = 0
g(sinθ - μcosθ) = 0
sinθ - μcosθ = 0
sinθ = μcosθ
μ = sinθ/cosθ
μ = tanθ
μ = tan20
μ = 0.3639702342...
μ = 0.36
HELPPPP
The maximum force of sliding friction between a 10 kg rubber box and the concrete
floor is 64 N. How much force should a worker push on the box with if he wants it to
move at a constant velocity?
1) A little less than 64 N
2)A little more than 64 N
3)Exactly 64 N.
4)Exactly 640 N
The force that will move the box at constant velocity must be a little more than 64 N.
The coefficient of sliding friction is obtained from the formula;
μ= F/R
Where;
F = frictional force
μ = coefficient of sliding friction
R = Normal reaction
It is necessary to note that the force that will move the body must be greater than the frictional force acting between the body and the surface in order to move the body. Hence, the force that will move the box at constant velocity must be a little more than 64 N.
Learn more: https://brainly.com/question/11969651
Find the angle between two equal forces (p) when their resultant is equal to (p)
Answer:
60°
Explanation:
It will be equilateral triangle, you can prove with the cosine theorem.
1)P^2=P^2+P^2 - 2×P×P× cos A
2) cos A= P^2 / 2× P^2 = 1/2
cos A = 1/2
A = 60°
If you wrote this question right,it will be solved like this :)
Choose the items that are examples of unalienable rights.
A) criticizing the government
B) to live wherever you want to
C) the government requiring safety standards in cars
D) preventing unpopular religions from holding services
E) not having the government listen to your phone calls
I NEED HELP ASAP
Answer:
the answer is D
Explanation:
bc the goverment cannot stop any religion from its service
The examples of unalienable rights include:
To live wherever you want to.The government requiring safety standards in cars.Not having the government listen to your phone calls.In the declaration of Independence, the unalienable rights include life, liberty, and the pursuit of happiness.
It should be noted that one can live wherever one wants to. Also, one has the right to religion and should not be disturbed from practicing their religion. The government doesn't have the right to listen to one's phone calls too.
In conclusion, the correct options are A, C, and E.
Read related link on:
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giúp em toàn bộ nhé ............
Explanation:
nnnnkgcbchg of bbjbjk oh jjzjjzkedkkdkfjjsjdsjfkjfdkkdowkronqfojofj see j FC
Which statement describes friction?
Answer:
include the statements pls so i can choose wich one it is and tell you
Explanation:
HELP PLEASE
What is the correct definition of amplitude?
A. the height of a wave
B. the distance between two crests or troughs
C. the number of complete waves that pass a point in a second
D. the time it takes for one complete wave to pass a given point
Answer:
correct answer is A) the height of a wave
Explanation:
i just did the test:)
The amplitude is used represent the height of the wave.
What is wave?A wave is a disturbance in a medium that carries energy without a net movement of particles. In general, waves are classified into two types as Longitudinal and Transverse
Given is the amplitude of a wave.
Amplitude of a wave is equal to measure of the length of crest or trough. Crest and trough are the points that represents the maximum and minimum displacement of the wave with respect to the reference axis. The crest and the trough points are both at a equal straight line distance from the reference axis. This distance is also called height of the wave. The amplitude is the distance between the centerline and the Crest or trough. The general equation representing the amplitude of wave is x = A sin (ωt + ϕ) or x = A cos (ωt + ϕ) is the formula.
Therefore, the amplitude represents the height of the wave.
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A dry cell gives static electricity true or false?
Answer:
False
Explanation:
Give two examples of contact and non-contact forces and explain why they are contact and non-contact forces respectively.
The Two examples of contact forces are:
frictional force Contact force.The two examples of non contact forces are:
Gravitational forcemagnetic force.Contact forces happens due to the contact between two objects
Non Contact forces happens because there is no contact between two objects. There is no attraction.
Which requires more work, lifting a 20 kg box vertically 2 meters OR lifting a 10 kg box 4 meters? Explain.
Answer:
I'm not sure in which direction 10kg is lifted but assuming 10kg is lifted (or dragged) horizontally then
the 20kg vertically requires more work because gravity pushing down on it will require a somewhat large output of Energy.
But if they are both lifted vertically (or horizontally)then they are equal in work.
Hope this helps
If Brad drives 100 meters forwards and then 100 meters backwards, what is her
distance? Her displacement?
Answer:
0 because she went to exact same place as before
PLZ!!!!!!!!!!!!!!!!!!!! HELP, I'll mark brainliest, JUST HELP!!!!!!!!!!!!!!!!
1. A rocket has a mass of 0.8 kg and an engine that provides 100 N of force. A second rocket is being designed to use the same engine but accelerate at half the rate of the first rocket. What is the mass of the second rocket?
a. 0.4 kg
b. 1.6 kg
c. 2.4 kg
d. 0.8 kg
2. Which of the following would be a situation with unbalanced forces?
a. Two people pulling on the same side of a wheelbarrow
b. A team of players in tug of war pulling on the rope, each team with equal numbers of people pulling with equal strength
c. Two people of opposite sides of a big tire. One pushes the tire and one pulls it with equal force
d. Two people not touching a crate that is sitting stationary.
3. Why is it generally easier to push a heavy object that is already moving instead of the same heavy object that is stationary
a. The force of gravity on the object is different if it is stationary or not.
b. The force of friction on the object is different if it is stationary or not
c. The force of the push on the object is different if it is stationary or not
d. The normal force on the object is different if it is stationary or not.
Thanks In Advance!! (I will mark brainliest) :)
Answer:
1. A. 0.4 kg
2. B. A team of players in tug of war pulling on the rope, each team with equal numbers of people pulling with equal strength
3. If an object is stationary the net force is zero.
3. B. The force of friction on the object is different if it is stationary or not
Explanation:
2. If two tug of war teams were pulling with the same force, neither team would move the rope would be at a stand still.
Answer:
The above person to the right is correct except for Number 2. The answer for that will be a.
Explanation:
Remember that equal is a big hint that the scenario is balanced forces since all forces are canceling out thus the object doesn't move. In a. two people are pulling a wheel barrel on the same side. This means one side has more force than the other hence the wheel barrel moves.
Which can occur during a physical change? (SELECT ALL THAT APPLY!.)
The amount of energy within a substance can change.
The shape of a piece of matter can change.
The chemical reaction produces a new substance.
The atoms of the substance can permanently change.
Answer:
C, B, and D are ones i think i know that can occur during a physical change
Explanation:
When the pushing force is increased to 88.2 N, the box just begins to move. What is the Friction Force if it is moving at a constant velocity? What is the coefficient of friction between the ground and box?
In order to calculate frictional force look below..
The formula given by
[tex]\\ \sf\longmapsto F_f=\mu N[/tex]
Or
[tex]\\ \sf\longmapsto F_f=\mu mg[/tex]
u is coefficient of friction
N is normal reaction.
How does the mass of the bob affect the number of swings of a pendulum?